Security system

ABSTRACT

An electrooptical intruder detection system including alignable emitting and detecting elements, such as semiconductor diodes. Each element is disposed in a holder member having a semispherical head portion which cooperates with a mounting plate and retainer member to provide the alignment function. In addition, the emitting element may be mounted in an adapter member which is axially adjustable relative to the holder member. Installation in an electrical outlet having various apertures for exposing the electrooptical element and permitting connection to external electrical devices is preferred.

United States Patent [72] Inventor David R. Matthews Ann Arbor, Mich.[211 Appl. No. 820,378 [22] Filed Apr. 30, 1969 [45] Patented Nov. 9,1971 [73] Assignee Laser Systems Corporation Ann Arbor, Mich.

[54] SECURITY SYSTEM 10 Claims, 5 Drawing Figs. [52] US. Cl 250/221,250/239, 250/234, 340/258 [51] Int. Cl G08b 13/00 [50] Field of Search.1 250/221 222, 239, 234; 340/276, 227, 258

[56] References Cited UNITED STATES PATENTS 2,918,585 12/1959 Farmer250/239 2,919,353 12/1959 Paradise 250/239 3,029,348 4/1962 Heinz250/222 X i O PTl C AL PA TH 3,197,646 Anders et al 250/222 3,293,98012/1966 De Benedetti 250/205 X 3,294,901 12/1966 Stanghi 250/239 X3,408,501 10/1968 Thompson 250/239 3,488,510 l/1970 Raymond, Jr. et al.250/222 3,529,200 9/1970 Potter et al. 250/217 X Primary ExaminerWalterStolwein Attorney-Barnard, McGlynn & Reising l I L; I III} I ROCESSOR I8, ALARM Z0 PATENTEBN 9 AMPLIFIER 8. ALARM POCESSOP AMPLIFIER & ALARM ALPATH POWER & 30 SUPPLY Wm "K. M. 0m

ATTORNEY SECURITY SYSTEM This invention relates to security systems ofthe type having a transmitter and a receiver disposed in signal transferrelation along a predetermined line of sight and, more particularly, tosuch a security system which includes improved apparatus for concealingand aligning the various elements thereof for optimum signal transfer.

Copending application for patent, Ser. No. 816,727, filed in the name ofDavid R. Matthews, discloses a security system employing anelectro-optical pulse transmitter and an electrooptical receiverdisposed in signal transfer relation such that the presence of anintruder in the line of sight between the transmitter and receiverresults in the loss of pulses at the receiver. The loss of apredetermined number of such pulses produces an alarm signal indicatingthe presence of an intruder. In many instances it is highly desirable toconceal the transmitter and receiver apparatus of such a system byinconspicuous appearance and, further, to provide convenient means bywhich the transmitter and receiver can be aligned with the predeterminedline ofsight to provide optimum signal transfer and system performanceunder various conditions. The present invention is particularly suitedto satisfy such objectives.

In accordance with the present invention, a security system such as thatdescribed in the aforementioned copending application or any similarsystem employing a defined signal beam may be'aligned for optimum signaltransfer along a predetermined line of sight. In general, this isaccomplished by the provision of a holder member for an electro-opticalelement, such as a diode, together with mounting means for permittingthe alignment of the holder member with the line of sight.

In a preferred fonn, the holder member comprises a hollow cylindricalmember having a head portion carrying the electro-optical elementadjacent an aperture defining a signal path and a mounting plate havinga portion for retainingly receiving the head portion of the holdermember in variably alignable engagement therewith. This apparatus may beused in either the transmitter or the receiver, but preferably in both,and permits the variouselectronic packages which, in themselves, requireno alignment, to be mounted separately from the electro-optical elementsand the associated holder members.

In accordance with the invention the holder member may be easilyconcealed such that only the aperture in the head portion is exposed. Ina preferred embodiment, the mounting plate for the holder member takesthe form of a common electrical outlet having various apertures forreceiving plug prongs and ground prongs. Such an arrangement not onlypermits concealment of the holder within the outlet but also facilitatesthe electrical connection of apparatus such as external power suppliesand meters to the electronic packages through the apertures of theelectrical outlet.

The invention, as well as the various features and advantages thereof,may be best understood by reference to the following description of anillustrative embodiment. This description is to be taken with theaccompanying drawings of which:

FIG. 1 is a schematic diagram of a typical security system which mayemploy the invention;

FIG. 2 is a plan view of a mounting structure in the form of anelectrical outlet;

FIG. 3 is a side view in cross section of a preferred mountingstructure;

FIG. 4 is a block diagram indicating the preferred connection pattern ofthe receiver apparatus; and

FIG. 5 is a side view in cross section of a preferred holder assembly.

FIG. 1 illustrates a security system including an infrared pulse signaltransmitter for directing signals toward an electro-optical receiver 12along a line of sight defined by the indicated optical path."Transmitter 10 includes an electro-optical signal emitter such as agallium arsenide diode disposed in a holder member 16 and electricallyconnected to a pulser 18 such as a multivibrator or a relaxationoscillator. Pulser 18 is connected to a DC power supply 20 and suppliesa continuous train of narrow current pulses to the electro-opticalemitting element for the generation of optical pulses in the infraredfrequency range. Holder 16 is disposed in mounting apparatus includingthe combination of a plate 22 having an aperture 23 which engages theholder 16 in such a fashion as to permit various angular orientationsand alignment of the holder 16 with the line of sight to the receiver12. The mounting apparatus further includes a retainer member 24 whichalso engages the holder 16 to maintain it in engagement with the plate22.

Receiver 12 includes an eIectro-optical element, such as a silicondiode, disposed in a holder 26 so as to be responsive to the opticalsignals from transmitter 10 to produce a varying electrical signal. Thissignal is coupled to amplifier 28 which receives power from DC source30. The amplified receiver signals are connected into a signal processorand alarm device 32 which responds to the absence of receiver pulses fora given interval to produce an alarm signal. Holder 26, which isgenerally similar to transmitter holder 16, is mounted in a plate 34having an aperture 35 which receives and engages the holder 26 andpermits alignment thereof with the optical path of the signal fromtransmitter holder 16. Holder 26 is maintained in engagement with plate34 by a retainer member 36.

FIG. 5 illustrates in detail the construction of the transmitter holder16. Holder 16 is of generally cylindrical configuration and includes ahollow head portion 38 of semispherical internal configuration and atubular body portion 40. Head portion 38 includes an axially alignedcavity 42 within which is disposed a planar gallium arsenide diode 44preferably, but not necessarily, of the nonlasing type. Cavity 42temtinatesat the forward boundary of head portion 38 in an aperturewithin which is disposed a convex lens 46 for collimating the infraredsignals produced by the diode emitting element 44. The tubular bodyportion 40 includes an internally threaded neck portion 48 whichreceives an externally threaded adapter member 50 of cylindricalconfiguration in axially adjustable engagement therewith. The emittingdiode element 44 is soldered or otherwise suitably secured to the endportion of the adapter member 50 so as to be within cavity 42. Adapter50 is axially adjustable in its relationship with holder 16 to permitprecise location of the emitting element 44 at the focal point of lens46. Emitter element 44 is electrically connected to an insulatedconductor 52 which in turn is connected to the pulser 18 as showninFIG. 1. A second insulated lead 54 is connected to the electricallyconductive body of adapter member 50 and also extends to the pulser 18as shown in FIG. 1 The holder 16 is preferably constructed of a phenolicmaterial so as to be electrically insulative.

The receiver holder 26 may also be constructed in the manner shown inFIG. 5 but, as a practical matter, need not be provided with theadjustable adapter member 50. Rather, the infrared signal-responsiveelement of the receiver holder 26 may be permanently secured within thecavity since precise focusing in the receiver portions is not required.

FIGS. 2 and 3 illustrate a preferred form of the mounting elements forboth the transmitter and receiver holder members, but will be describedwith particular reference to the receiver 12, it being understood-that asimilar structure may be employed in the transmitter 10. Mounting plate34 is con structed in the form of a commonplace electrical wall outlethaving an upper double prong receptacle 56 and a lower double prongreceptacle 58. The upper receptacle 56 includes a pair of plug prongreceptacles 60 and a ground prong receptacle 62 disposed in the ordinaryphysical relationship to one another. Similarly, the lower receptacle 58includes a pair of plug prong apertures 64 and a ground prong aperture66. The plug prong apertures 60 and 64 may be internally modified toaccept only a plug of specified configuration thereby to prevent theinadvertent admission of a standard plug for some commonplace electricalappliance.

As best shown in FIG. 3, the ground prong aperture 62 is contiguous withand axially aligned with a semispherical socket portion 68 which extendsthrough the rear surface of the plate 34 to receive the head portion 70of the receiver holder member 26. Head portion 70 is also ofsemispherical configuration and carries a lens 72 in the forward portionthereof in the same manner as the transmitter holder 16 described withreference to FIG. 5. Universal movement is permitted between headportion 70 and the socket portion 68 of the plate 34 to accomplish thealignment function. To maintain the holder 26 in the desired position aretainer member 36 is suitably adapted for interconnection with theplate 34 and includes an aperture 74 of semispherical configuration toengage and retain the rear of the head portion 70 of holder member 26 asshown in FIG. 3.

By installing the transmitter holder member 16 and the receiver holdermember 26 in the mounting structure described in FIGS. 2 and 3, auniversal type swiveling action is permitted between the head portionsof the holder members and the engaging mounting structure to permitaxial alignment of the two holder members and the two electro-opticalelements associated therewith in a common line of sight. Moreover, thetransmitter member 16 further permits a precise focusing of the opticalsignals into a collimated beam which then may be directed toward thereceiver element. Since the holder members 16 and 26 are physicallyseparate from their associated electronics modules, as shown in FIG. 1,the alignment function is facilitated and the space within which thealignable elements are disposed may be held to a minimum.

FIG. 4 illustrates a receiver installation which facilitatesconcealment, access, and operation of the system. The amplifier 28 andsignal processor and alarm device 32 are shown disposed within anelectrical outlet box 76 of the type which may be conveniently installedin any wall. Receiver holder member 26 is disposed in the upperreceptacle 56 of the double outlet plate 34 and retained in position bythe retainer member 36 in the manner described with reference to FIGS. 2and 3. Optical signals are thus received by the silicon diode disposedwithin holder member 26 through the ground prong aperture 62 and theexposed lens 72. Electrical signals produced by the detector diode arecoupled into amplifier 28 through electrical conductors 78 and thence tothe signal processor and alarm device 32 through conductors 88. Powersupply 30 is connected to the amplifier 28 and the processor alarm 32through a cord 80 and plug 82 of the double prong type which isconveniently inserted into the plug prong apertures 64 of the lowerreceptacle 58. The plug prong apertures 64 may be provided with suitableconductor means including lines 84 for connection to the amplifier 28,and lines 86 to the processor-alarm 32. Power supply 30 may be concealedin a common electrical appliance such as a lamp base to thereby assumean inconspicuous appearance. Upon initial installation of the system andfrom time to time during the operation of the system, it maybe desirableto realign the receiver holder member 26 with the transmitter holdermember 16. This may be readily accomplished by removal of a cover plate90 to allow access to the apparatus within the box 76. A meter 92 may beprovided with a plug 94 having a pair of prongs which are received bythe plug prong apertures 60 of the upper outlet portion 56. The interiorof the apertures 60 are connected by means of electrical conductors 96to an output of amplifier 28 to monitor the amplitude of the electricalsignal produced by the amplifier. in the alignment process thetransmitter pulser 18 is turned on to direct pulses toward the receiverholder member 26. The receiver and holder members are varied inalignment until a peak reading is obtained on meter 92. At this point,the receiver holder members are suitably aligned and the cover plate 90may be reinstalled after disconnecting the meter plug 94 from the upperoutlet portion 56.

Although the invention has been described with reference to a specificembodiment, it is to be understood that the invention is not to belimited thereby.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

l. in a security system of the type having a signal transmitter and asignal receiver alignable in signal transfer relation along a commonline of sight; a transmitter device comprising a holder member having agenerally spherical and hollow head portion and a shank portion integraltherewith, an electrically actuable radiant energy emitter in the headportion, a support plate having a socket therein to adjustably receivethe head portion, and a retainer member engageable with the plate andthe head portion to maintain the head portion in engagement with thesocket to permit substantially universal adjustment of the holder toestablish said line of sight, a lens disposed in the head portion suchthat radiant energy from the emitter passes therethrough, the plateincluding a pair of apparent plug prong apertures and an apparent groundprong aperture arranged to appear as an electrical wall outlet, saidsocket being contiguous with the ground prong apertures such that theline of sight extends therethrough.

2. Apparatus as defined in claim 1 including an adapter member axiallyadjustably disposed within the shank portion and carrying the emitter topemiit adjustment in the spacing between the emitter and lens.

3. Apparatus as defined in claim 1 wherein the emitter is a diode.

4. in a security system; a transmitter device for transmitting a radiantenergy beam and a receiver device in the path of the beam for receivingthe beam and indicating an interruption thereof, mounting means for atleast one of the devices including a plate having first and second pairsof parallel apparent prong apertures and first and second apparentground prong apertures therein to appear as an electrical wall outlet,said one device being adjustably supported by the plate such that thebeam path extends through one of the ground prong apertures thereto.

5. Apparatus as defined in claim 4 wherein said one device is a receiverdevice, the combination further including signal processing meanselectrically connected to said receiving device for producing signalsindicating the interruption of the beam directed thereto.

6. Apparatus as defined in claim 5 including a power supply having adouble-prong plug for insertion in one of said first and second pairs ofparallel prong apertures, and electrical connector means connecting saidapertures to said one device.

'7. Apparatus as defined in claim 6 including monitoring means andelectrical connector means for connecting the monitor means through oneof said first and second pairs of said parallel prong apertures to saidsignal processing means.

8. Apparatus as defined in claim 4 wherein said one device is aphotoelectric device and means mounting said photoelectric device tosaid plate for permitting limited universal adjustment in the viewingdirection thereof.

9. Apparatus as defined in claim 8 wherein said means for permittinguniversal adjustment includes a spherical shaped holder carrying saidphotoelectric device and means including a portion of said platedefining a socket for receiving said spherical holder.

10. Apparatus as defined in claim 9 wherein said holder includes a lensalignable with said ground prong aperture so as to lie in the beam path,and means for adjusting the axial distance between said photoelectricdevice and the lens for focusing purposes.

i i i 1

1. In a security system of the type having a signal transmitter and asignal receiver alignable in signal transfer relation along a commonline of sight; a transmitter device comprising a holder member having agenerally spherical and hollow head portion and a shank portion integraltherewith, an electrically actuable radiant energy emitter in the headportion, a support plate having a socket therein to adjustably receivethe head portion, and a retainer member engageable with the plate andthe head portion to maintain the head portion in engagement with thesocket to permit substantially universal adjustment of the holder toestablish said line of sight, a lens disposed in the head portion suchthat radiant energy from the emitter passes therethrough, the plateincluding a pair of apparent plug prong apertures and an apparent groundprong aperture arranged to appear as an electrical wall outlet, saidsocket being contiguous with the ground prong apertures such that theline of sight extends therethrough.
 2. Apparatus as defined in claim 1including an adapter member axially adjustably disposed within the shankportion and carrying the emitter to permit adjustment in the spacingbetween the emitter and lens.
 3. Apparatus as defined in claim 1 whereinthe emitter is a diode.
 4. In a security system; a transmitter devicefor transmitting a radiant energy beam and a receiver device in the pathof the beam for receiving the beam and indicating an interruptionthereof, mounting means for at least one of the devices including aplate having first and second pairs of parallel apparent prong aperturesand first and second apparent ground prong apertures therein to appearas an electrical wall outlet, said one device being adjustably supportedby the plate such that the beam path extends through one of the groundprong apertures thereto.
 5. Apparatus as defined in claim 4 wherein saidone device is a receiver device, the combination further includingsignal processing means electrically connEcted to said receiving devicefor producing signals indicating the interruption of the beam directedthereto.
 6. Apparatus as defined in claim 5 including a power supplyhaving a double-prong plug for insertion in one of said first and secondpairs of parallel prong apertures, and electrical connector meansconnecting said apertures to said one device.
 7. Apparatus as defined inclaim 6 including monitoring means and electrical connector means forconnecting the monitor means through one of said first and second pairsof said parallel prong apertures to said signal processing means. 8.Apparatus as defined in claim 4 wherein said one device is aphotoelectric device and means mounting said photoelectric device tosaid plate for permitting limited universal adjustment in the viewingdirection thereof.
 9. Apparatus as defined in claim 8 wherein said meansfor permitting universal adjustment includes a spherical shaped holdercarrying said photoelectric device and means including a portion of saidplate defining a socket for receiving said spherical holder. 10.Apparatus as defined in claim 9 wherein said holder includes a lensalignable with said ground prong aperture so as to lie in the beam path,and means for adjusting the axial distance between said photoelectricdevice and the lens for focusing purposes.